I'm doing homework for Inorganic Chemistry, and I am a little confused.
The Question is:
What is the electronic configuration of $\ce{Ru^{2+}}$?
If I were to remove from the highest energy level it would be $\ce{[Kr]~5s^1~4d^5}$ leaving $6$ unpaired electrons.
If I were to take into account electron pairing it would be $\ce{[Kr]~4d^6}$ with $4$ unpaired electrons.
What would be the correct approach?